In industrial process measurements technology, especially for automation of chemical processes or procedures for producing a product from a raw or starting material by the use of chemical, physical or biological processes and/or for control of industrial plants, measuring devices installed near to the process, so-called measuring field devices and/or actuators installed near to the process, such as control elements or valves, are applied. These devices installed near to the process are also referred to as field devices. Field devices embodied as sensors can monitor, for example, process measurement variables, such as pressure, temperature, flow, fill level or measured variables of liquid or gas analysis, such as pH-value, conductivity, concentrations of certain ions, chemical compounds and/or concentrations or partial pressures of gases.
In a production plant, frequently a large number of the most varied of field devices are used. A field device arranged at a certain location in the process, for example, a sensor installed at a certain location and embodied for registering one or more measured variables, forms a measuring point. A measuring point can also comprise a plurality of sensors and/or actuators arranged at a shared location of installation in the immediate vicinity of one another for registering the same or different measured variables of the process at this location of installation. For example, a measuring point can comprise a temperature sensor and a pH sensor, which register the temperature and the pH-value of the medium present at the location of installation.
Sensors include, as a rule, a measuring transducer, which is embodied to register the monitored measured variable and to produce an electrical measurement signal correlated with the current value of the measured variable. For additional processing of the measurement signal, the sensor includes a sensor electronics, which is embodied further to condition the electrical measurement signal, for example, to digitize it or to convert it into a derived variable, and, in given cases, to output the result to a superordinated unit.
In the case of sensors of the aforementioned type, the particular sensor electronics is frequently electrically connected with a superordinated electronic data processing system arranged most often spatially removed and, in given cases, also spatially distributed relative to the respective measuring point. Measured values produced by the respective sensor, diagnosis relevant data and other sensor data are forwarded to the superordinated electronic data processing system. Also actuators are correspondingly connected with the electronic data processing system for the purpose of their control. The superordinated data processing system can especially have one or more electronic process controllers, for example, one or more measurement transmitters located on-site or programmable logic controllers (PLC) or one or more process control computers installed in a remote control room.
Serving, at least sectionally, for data transmission in such industrial data processing systems are fieldbus systems, such as e.g. Foundation Fieldbus, Profibus, etc. or, for example, also networks based on the Ethernet standard as well as the corresponding, most often application independently standardized, transmission protocols.
Field devices include for communication with the superordinated data processing system frequently a transceiver, which is embodied to receive signals from the superordinated data processing system, for example, a control unit such as a PLC or a process control computer, respectively to output signals from the field device to the superordinated data processing system.
Thus, the sensor electronics of many sensors includes a transceiver, which is embodied to convert the electrical, in given cases, digitized, measurement signals of the sensor into a signal transmittable according to a transmission protocol processable by the fieldbus system and by the superordinated data processing system and to output such to the superordinated data processing system. Moreover, the transceiver is embodied to receive signals, data and/or control commands from the superordinated data processing system, especially a PLC or a process control computer, and, in given cases, to condition and/or to process such. Such sensors are known, for example, from DE 10 2008 029 956 A1 (US 2010026518) or DE 10 2011 107 717 A1 (U.S. Pat. No. 8,766,168). These sensors come frequently without their own display system or input means. In this case, display of measured values, respectively input of parameter data or other data and/or commands, can occur by means of the superordinated data processing system, e.g. by means of a PLC or a process control computer. Similar options exist for actuators.
If on-site, i.e. at the location of installation of the field device, a maintenance measure is to be performed, or if a service technician requires, on-site, the current measured value or other sensor data registered by a field device embodied as a sensor, respectively the maintenance measure requires the input of parameters and/or control commands into the sensor electronics, an on-site applicable display and/or service device is required. This plays a role especially in the case of more maintenance intensive measuring points, for example, in the case of measuring points, where electrochemical or optical sensors for gas- and liquid analysis are applied. These sensors or at least parts of these sensors must regularly be calibrated, adjusted, cleaned or replaced.
Described in German Gebrauchsmuster DE 20 2012 102138 U1 is an arrangement for the read-out of identification information of a field device by means of a separate, portable, read-out unit, wherein associated with the field device is a readable identification, which includes at least one 2-D code, especially a QR code or a data matrix code. The identification information can be applied on a tag, which is connected, e.g. adhered or attached to the field device. If the location of installation of the field device is difficultly accessible for a service technician, the tag can also be placed at a site remote from the field device and more easily accessible. The read-out identification information is used in the case of the arrangement described in DE 20 2012 102 138 U1, in order to retrieve from a database other information concerning the field device, also when the field device itself does not have a display system and a display system of a superordinated data processing system is not available on-site.
Known from German Patent DE 10 2009 028 794 A1 is a measuring apparatus for determining a physical or chemical, measured variable, which includes a sensor unit and a mobile service unit, e.g. a mobile telephone. The service unit is embodied to communicate with the sensor unit, wherein associated with the sensor unit is a transceiver unit, which has a first communication means, in order to receive data from the sensor unit and to transmit data to the sensor unit. The transceiver unit also has a second communication means, which includes an interface to a telecommunications network, in order to transmit data to the service unit and to receive data from the service unit, which likewise has an interface to the telecommunication-network. Disadvantageous in this measuring apparatus is that the service device for servicing a sensor unit must use the particular address of the sensor unit in the telecommunication-network. If the service device is used for servicing a large number of different sensors of a complex process installation, always the right address of the respective measuring device must be identified and the corresponding connection established. A further disadvantage is that the transceiver unit associated with the sensor unit must have a second communication means with interface to the telecommunication-network, in order to enable communication with the service device. This causes additional manufacturing costs for the measuring apparatus.